Refrigerant control mechanism for evaporators



y 1934:. F. G. SLAGEL REFRIGERANT CONTROL MECHANISM FOR EVAPORATORS Filed Jan. 9, 1930 gwuwntoc W 0. J

Patented May 1, 1934 TED STAT S PATENT OFFICE REFRIGERANT CONTROL MECHANISM FOR EVAPOR-ATORS Application January 9, 1930, Serial No. 419,720

Claims.

This invention relates to refrigerating systems, and more particularly to mechanism for controlling the flow of refrigerant into an evaporator.

A float actuated valve is commonly employed to control the flow of liquid refrigerant through a passage in an evaporator wall to automatically maintain a constant quantity of refrigerant in the evaporator. Usually, the valve employed is of the needle type which is freely mounted in the evaporator wall, being moved to a seating position by a pivoted float in the evaporator and being opened by refrigerant pressure when the float moves in a direction to permit an unseated valve position, such arrangement resulting because of an arcuate movement of the float and a reciprocating movement of the valve.

Because of the character of the refrigerant, the materials of which the evaporator and valve are constructed and the presence of oil, the valve 'often becomes stuck by corrosion and other causes, and as the valve movement is not positive, refrigerant flow into the evaporator either ceases or is free. This condition requires objectionable servicing, inconvenience, and often 7 entire replacement of the evaporator.

An object of my invention is to provide a valve mechanism for controlling the flow of refrigerant into the evaporator of a refrigerating system which will be positively seated and unseated by the rise and fall of a float in the evaporator.

Another object of my invention is to provide a valve inlet mechanism for flooded evaporator-s in which a needle valve is releasably associated with and positively actuated by a float within the evaporator.

A further object of my invention is to provide an inlet valve mechanism in which a needle valve is reciprocated in a limited non-rotatable manner by a pivoted float within the evaporator.

Still another object of my invention is to provide a float actuated valve and seat assembly which can be bodily removed and associated from the exterior of the evaporator without disturbing the float within the evaporator.

Other objects of the invention will appear from the following description taken in con nection with the drawing. which forms a part of the specification, and in which:

Fig. 1 is a vertical sectional view of an evaporator unit having my invention incorporated therein; Fig. 2 is a fragmentary horizontal sec tional view of the valve mechanism; and Fig. 3 is a sectional view taken on line 33 of Fig. 2.

Referring to the drawing by characters of reference, represents generally an evaporator unit which is connected in circuit with the condenser and compressor (not shown) of a mechanical refrigerating system. The evaporator vessel 11 is cylindrical in form, and has an open end which is sealed by the end plate 12 which is soldered, or otherwise fixed thereto. A union 13 is fixed to the upper portion of the end plate by the cap screws 14 providing a connection for the refrigerant return conduit leading back to the compressor, the end plate having an outlet opening 15 communicating with the union and receiving the outlet tube 16. Another union 1'? is secured to the lower portion of the end plate by cap screws 18 and provides a connection for the refrigerant conduit leading from the con- 7o Within the vessel is provided mechanism for automatically maintaining a substantially constant body of liquid refrigerant therein. The interior face of the end plate is formed with a boss 21 through which the passage 19 also extends, there being an outlet passage 22 communiso cating therewith. A pair of spaced arms 23 project from the end plate adjacent the sides of the boss, and a float bracket 24 extends between the arms and is pivotally carried on the pin 25 which extends through the bracket and is se- 85.

cured to the arms. An open float 26 is secured to the bracket 24 and is arranged to be partially submerged in the liquid refrigerant accumulation in the evaporator. The outlet tube 16 is bent downwardly so that an open end thereof extends into and adjacent the bottom of the float.

A removable body 27 is screwed into the passage 19 from the exterior of the end plate, when the union 17 is removed, and extends through the boss 21. The body is formed with a duct 28 establishing commimication between the union 1'? and the outlet passage 22 in the boss. A Valve seat member 29, formed of harder metal than the body, is pressed into the duct 28 from the inner end of the body and is provided with a passage therethrough which is opened or closed by the needle valve 30. The head of the removable body is formed with a circular edge 40 which is pressed against a shoulder in the end plate when screwed therein. The circular edge provides a contact to prevent leakage around the body.

As usually constructed, the float moves up and down with the level of the refrigerant in the evaporator vessel and when the level falls, through vaporization of the refrigerant which leaves through the tube 16, the float moves in a direction allowing refrigerant pressure in the inlet conduit to unseat the valve allowing refrigerant to flow into the evaporator. As the flow of refrigerant replenishes the accumulation in the evaporator, the float moves up and engages the needle valve moving it into seating engagement to stop the flow of refrigerant. There is usually no positive connection between the float and the needle valve, and the valve is free to rotate. Rotation of the valve is objectionable because the fit will usually allow leakage in some relations with the seat. Due to various causes, a free needle valve sticks to the seat because of corrosion, and the pressure of the refrigerant in the high side is not sufficient to open the same. As a result, refrigerant will not flow into the evaporator and the system fails until serviced.

In order to overcome the objections mentioned to the present valve control mechanism, I provide a connection between the needle valve and the float, and mount the needle valve so that it will reciprocate without rotation. To this end, the body is provided with a pair of slots 31 into which the ends of a pin 32, extending through the needle valve, project. The slots extend axially of the body thus permitting reciprocation of the valve without rotation. This arrangement also an chors the needle valve with the body so that it is secured therein and is removed with the body when it is unscrewed from the end plate, and by removing the pin the valve can be detached from the body.

The needle valve is formed with a circular groove 33 adjacent its inner end, and a connection 34 is provided with a pair of spring fingers 36 which extend into the groove and releasably engage the valve. The bracket is provided with an upstanding boss 36 having a vertical slot 37 into which the base of the connection is inserted, and the top of the slot is closed by deforming the bracket to retain the connection member with the bracket. The connection member is associated with the float so that the spring fingers will engage the end of the needle valve and positively engage the same during at least enough movement thereof to cause valve reciprocation sufficient to positively open and close the duct in the removable body, even though they move in different planes.

It will be seen that the body, with the seat and valve, can be removed as a unit from the exterior of the end plate when the union is detached, and that the valve will be readily released from the spring fingers by the withdrawal of the body and also reassembled therewith when the body is screwed back into the end plate. Furthermore, the valve can be readily detached from the body when it is removed from the evaporator. The valve is positively reciprocated by the float and can not rotate, the spring providing a positive connection even though the connection moves arcuately with the float while the valve reciprocates.

Although this invention has been described in connection with a certain specific embodiment, the principle involved is susceptible of numerous other applications which will readily occur to persons skilled in the art, and the invention is therefore to be limited only as indicated by the scope of the appended claims.

What I claim is:

1. In a flooded refrigeration evaporator, control mechanism comprising a reciprocable needle valve mounted in a passage in the evaporator Wall and controlling the flow of refrigerant through the passage, a pivoted float in the evaporator, and a connector fixed to the float and releasably attached to the valve, said valve being engageable or disengageable with the connector by axial movement relative thereto.

2. In a flooded evaporator, a wall having an inlet passage therethrough, a reciprocable valve in the wall passage controlling the flow of refrigerant therethrough, a pivoted float in the evaporator, and a connection fixed to the float and releasably associated with the valve to positively actuate the valve in its arcuate movement, said valve being engageable or disengageable with said connection by endwise movement relative thereto.

3. In a flooded refrigerant containing evaporator, a wall having an inlet passage, a reciprocably mounted needle valve in the passage and controlling the flow of refrigerant therethrough, a float pivoted in the evaporator, and a connection fixed to the float, said connection having resilient fingers releasably engaging the needle valve.

4. In a flooded refrigeration evaporator, a wall having an inlet passage therethrough, a needle valve reciprocabiy mounted in the passage and controlling the flow of refrigerant therethrough, said valve having a head projecting into the interior of the evaporator, a connection fixed to a float pivoted in the evaporator, said connection having spring fingers engaging the valve head, and means limiting the movement of the valve in a direction away from closed position.

5. In a flooded evaporator for refrigerating systems, a wall having a passage therethrough, an exteriorly removable body in the passage having a duct through which refrigerant can flow into the evaporator, a non-rotatable reciprocable needle valve in the body controlling the flow of refrigerant therethrough, a pivoted float in the evaporator, and a connection fixed to the float and releasably engaging the needle valve to reciprocate the same, said valve being slidably disengaged from the connection by axial movement.

FRANKLIN G. SLAGEL. 

